initial commit. not currently in a working state.

1 files changed, 103 insertions, 0 deletions

diff --git a/nexgb/xgb_help.go b/nexgb/xgb_help.go
new file mode 100644
index 0000000..adb97e0
--- /dev/null
+++ b/nexgb/xgb_help.go
@@ -0,0 +1,103 @@
+package xgb
+
+// getExtensionOpcode retrieves the extension opcode from the extensions map.
+// If one doesn't exist, just return 0. An X error will likely result.
+func (c *Conn) getExtensionOpcode(name string) byte {
+	return c.extensions[name]
+}
+
+func (c *Conn) bytesPadding(buf []byte) []byte {
+	return append(buf, make([]byte, pad(len(buf))-len(buf))...)
+}
+
+func (c *Conn) bytesString(str string) []byte {
+	return c.bytesPadding([]byte(str))
+}
+
+func (c *Conn) bytesStrList(list []Str, length int) []byte {
+	buf := make([]byte, 0)
+	for _, str := range list {
+		buf = append(buf, []byte(str.Name)...)
+	}
+	return c.bytesPadding(buf)
+}
+
+func (c *Conn) bytesUInt32List(list []uint32) []byte {
+	buf := make([]byte, len(list)*4)
+	for i, item := range list {
+		put32(buf[i*4:], item)
+	}
+	return c.bytesPadding(buf)
+}
+
+func (c *Conn) bytesIdList(list []Id, length int) []byte {
+	buf := make([]byte, length*4)
+	for i, item := range list {
+		put32(buf[i*4:], uint32(item))
+	}
+	return c.bytesPadding(buf)
+}
+
+// Pad a length to align on 4 bytes.
+func pad(n int) int { return (n + 3) & ^3 }
+
+func put16(buf []byte, v uint16) {
+	buf[0] = byte(v)
+	buf[1] = byte(v >> 8)
+}
+
+func put32(buf []byte, v uint32) {
+	buf[0] = byte(v)
+	buf[1] = byte(v >> 8)
+	buf[2] = byte(v >> 16)
+	buf[3] = byte(v >> 24)
+}
+
+func get16(buf []byte) uint16 {
+	v := uint16(buf[0])
+	v |= uint16(buf[1]) << 8
+	return v
+}
+
+func get32(buf []byte) uint32 {
+	v := uint32(buf[0])
+	v |= uint32(buf[1]) << 8
+	v |= uint32(buf[2]) << 16
+	v |= uint32(buf[3]) << 24
+	return v
+}
+
+// Voodoo to count the number of bits set in a value list mask.
+func popCount(mask0 int) int {
+	mask := uint32(mask0)
+	n := 0
+	for i := uint32(0); i < 32; i++ {
+		if mask&(1<<i) != 0 {
+			n++
+		}
+	}
+	return n
+}
+
+// DefaultScreen returns the Screen info for the default screen, which is
+// 0 or the one given in the display argument to Dial.
+func (c *Conn) DefaultScreen() *ScreenInfo { return &c.Setup.Roots[c.defaultScreen] }
+
+// ClientMessageData holds the data from a client message,
+// duplicated in three forms because Go doesn't have unions.
+type ClientMessageData struct {
+	Data8  [20]byte
+	Data16 [10]uint16
+	Data32 [5]uint32
+}
+
+func getClientMessageData(b []byte, v *ClientMessageData) int {
+	copy(v.Data8[:], b)
+	for i := 0; i < 10; i++ {
+		v.Data16[i] = get16(b[i*2:])
+	}
+	for i := 0; i < 5; i++ {
+		v.Data32[i] = get32(b[i*4:])
+	}
+	return 20
+}